Morphological Characteristics of the Lacrimal Apparatus in its Obstruction of Various Genesis

Purpose: morphological assessment of the lacrimal ducts at various anatomical levels in patients with primary (PANDO) and secondary (SALDO) obstruction after radioactive iodine therapy.Methods. The material was obtained during endoscopic dacryocystorinostomy with revision of Hasner's valve in patients with PANDO (n=7) in the distal segments of the nasolacrimal duct and in patients with SALDO (n=7) after radioactive iodine therapy. During the surgery, a biopsy of Hasner's valve, as well as a biopsy of the lacrimal sac wall were performed. The resulting material was stained with hemotoxylin and eosin, alcyan blue and by Masson method. Morphological and morphometric analyses were performed in semi-automatic mode. The results of histochemical staining of sections were translated into points taking into account the area and optical density (chromogenicity) in relative units: 1 – weak (0 – 0.3); 2 – moderate (0.3 – 0.6); 3 – significant (>0.6). The nonparametric Mann-Whitney criterion was used for statistical analysis. The differences were considered significant at p<0.05.Results. The comparative morphological study both confirmed the available information concerning the radiation nature of the obstruction and allowed to quantify the fibrosis level of the stromal component and other lacrimal ducts structures.Conclusion. It was shown that the nasolacrimal duct sclerosis is significantly lower (p=0.029) in patients with SALDO than in patients with PANDO while fibrosis in the lacrimal sac is the same in patients of the compared groups.

The fingernail clams (Bivalvia: Veneroida: Sphaeriidae) of Morocco: Diversity, distribution and conservation status

In Morocco, many uncertainties surround the current diversity and distribution of the bivalve family Sphaeriidae. Such information, including taxonomy and conservation status, are vital for further studies to improve the knowledge of this family in Morocco and represents the first step towards the development of a national conservation plan for all freshwater bivalves. Between 2016 and 2019, several investigations were carried out to assess the diversity and distribution of Sphaeriidae in the different basins of Morocco, covering different types of habitat (lakes, springs, rivers and small ponds). The identification of specimens and their morpho-ecological features was based on morphological and morphometric analyses. The data on the general distribution of the collected species allowed the evaluation of their conservation status as well. The shell morphology and morphometric analyses revealed the existence of five species belonging to the genus Pisidium [P. casertanum (Poli, 1791), P. (cf.) personatum Malm, 1855, P. subtruncatum Malm, 1855, P. amnicum (O. F. Müller, 1774) and Pisidium sp.] and one species to the genus of Musculium [M. lacustre (O. F. Müller, 1774)]. Sphaeriidae were found in all Moroccan basins, except Bouregreg and Sakia El Hamra-Oued Eddahab Basins. The results showed that Sebou Basin was the species richest with the occurrence of the five species, while Loukkos and Sous-Massa Basins had the lowest-species richness with one species only. The conservation status of sphaeriids in Morocco was evaluated for the first time and resulted in P. (cf.) personatum and P. subtruncatum being proposed as Least Concern and Vulnerable, respectively, while the status of Regionally Extinct is suggested for both species P. amnicum and M. lacustre. First evaluation of the diversity and species richness of the family Sphaeriidae in Morocco with an assignment of an updated conservation status of the recorded species.

A Taxonomic Investigation into the Red Alga Plocamium within New Zealand

<p>The red alga Plocamium is a cosmopolitan genus, known for its distinct branching pattern and rich chemical composition. Recent studies indicate morphological-based species delimitation approaches have failed to accurately discern diversity, distributions, and evolutionary relationship between species worldwide. Currently there are seven recognized species within New Zealand based on traditional morphological approaches and no molecular based work focused on discerning true diversity of New Zealand species in this genus. This thesis is the first to use molecular-assisted alpha taxonomy to investigate Plocamium within New Zealand. Phylogenetic analyses (Maximum Likelihood and Bayesian Inference) based on COI, rbcL, LSU and combined LSU/COI markers, three molecular species delimitation methods (Automatic Barcode Gap Discovery, General Mixed Yule Coalescent, and Bayesian implementation of the Poisson Tree Processes), and morphometric analyses of various characters (width of main axis (WMA), width of lowest basal ramuli (WLBR), length of lowest basal ramuli (LLBR), number of alternating series of ramuli (NASR), average number of ramuli per alternating series (ANRAS), curvature of basal ramuli (CBR) and serrations present or absent from basal ramuli (SERBR) were used to address this topic. The species delimitation methods revealed at least eleven (A-K) putative genetic species (with some incongruences) within the New Zealand specimens included in the study. Morphometric analyses indicated morphology reflects genetic diversity when multiple measures of multiple characters are used, however this is not the case when considering single characters. Phylogenetic analyses revealed possible monophyly of New Zealand candidate species C-K, and possible relationships to Australian, Chilean, and Taiwanese species. However these backbone relationships were poorly supported. The results of this study indicate that Plocamium diversity within New Zealand has been underestimated and provide the first steps in discovering the true species diversity of Plocamium within New Zealand.</p>

A Taxonomic Investigation into the Red Alga Plocamium within New Zealand

<p>The red alga Plocamium is a cosmopolitan genus, known for its distinct branching pattern and rich chemical composition. Recent studies indicate morphological-based species delimitation approaches have failed to accurately discern diversity, distributions, and evolutionary relationship between species worldwide. Currently there are seven recognized species within New Zealand based on traditional morphological approaches and no molecular based work focused on discerning true diversity of New Zealand species in this genus. This thesis is the first to use molecular-assisted alpha taxonomy to investigate Plocamium within New Zealand. Phylogenetic analyses (Maximum Likelihood and Bayesian Inference) based on COI, rbcL, LSU and combined LSU/COI markers, three molecular species delimitation methods (Automatic Barcode Gap Discovery, General Mixed Yule Coalescent, and Bayesian implementation of the Poisson Tree Processes), and morphometric analyses of various characters (width of main axis (WMA), width of lowest basal ramuli (WLBR), length of lowest basal ramuli (LLBR), number of alternating series of ramuli (NASR), average number of ramuli per alternating series (ANRAS), curvature of basal ramuli (CBR) and serrations present or absent from basal ramuli (SERBR) were used to address this topic. The species delimitation methods revealed at least eleven (A-K) putative genetic species (with some incongruences) within the New Zealand specimens included in the study. Morphometric analyses indicated morphology reflects genetic diversity when multiple measures of multiple characters are used, however this is not the case when considering single characters. Phylogenetic analyses revealed possible monophyly of New Zealand candidate species C-K, and possible relationships to Australian, Chilean, and Taiwanese species. However these backbone relationships were poorly supported. The results of this study indicate that Plocamium diversity within New Zealand has been underestimated and provide the first steps in discovering the true species diversity of Plocamium within New Zealand.</p>

Quantifying asymmetry in non-symmetrical morphologies, with an example from Cetacea

Three-dimensional measurements of morphology are key to gaining an understanding of a species' biology and to answering subsequent questions regarding the processes of ecology (or palaeoecology), function, and evolution. However, the collection of morphometric data is often focused on methods designed to produce data on bilaterally symmetric morphologies which may mischaracterise asymmetric structures. Using 3D landmark and curve data on 3D surface meshes of specimens, we present a method for first quantifying the level of asymmetry in a specimen and second, accurately capturing the morphology of asymmetric specimens for further geometric analyses. We provide an example of the process from initial landmark placement, including details on how to place landmarks to quantify the level of asymmetry, and then on how to use this information to accurately capture the morphology of asymmetric morphologies or structures. We use toothed whales (odontocetes) as a case study and include examples of the consequences of mirroring landmarks and curves, a method commonly used in bilaterally symmetrical specimens, on asymmetric specimens. We conclude by presenting a step-by-step method to collecting 3D landmark data on asymmetric specimens. Additionally, we provide code for placing landmarks and curves on asymmetric specimens in a manner designed to both save time and ultimately accurately quantify morphology. This method can be used as a first crucial step in morphometric analyses of any biological specimens by assessing levels of asymmetry and then if required, accurately quantifying this asymmetry. The latter not only saves the researcher time, but also accurately represents the morphology of asymmetric structures.

Considerations for Post-processing Parameters in Mixed-Method 3D Analyses

ABSTRACTThe production of three-dimensional (3D) digital meshes of surface and computed tomographic (CT) data has become widespread in morphometric analyses of anthropological and archaeological data. Given that processing methods are not standardized, this leaves questions regarding the comparability of processed and digitally curated 3D datasets. The goal of this study was to identify those processing parameters that result in the most consistent fit between CT-derived meshes and a 3D surface model of the same human mandible. Eight meshes, each using unique thresholding and smoothing parameters, were compared to assess whole-object deviations, deviations along curves, and deviations between specific anatomical features on the surface model when compared with the CT scans using a suite of comparison points. Based on calculated gap distances, the mesh that thresholded at “0” with an applied smoothing technique was found to deviate least from the surface model, although it is not the most biologically accurate. Results have implications for aggregated studies that employ multimodal 3D datasets, and caution is recommended for studies that enlist 3D data from websites and digital repositories, particularly if processing parameters are unknown or derived for studies with different research foci.

Speciation in the deep: genomics and morphology reveal a new species of beaked whale Mesoplodon eueu

The deep sea has been described as the last major ecological frontier, as much of its biodiversity is yet to be discovered and described. Beaked whales (ziphiids) are among the most visible inhabitants of the deep sea, due to their large size and worldwide distribution, and their taxonomic diversity and much about their natural history remain poorly understood. We combine genomic and morphometric analyses to reveal a new Southern Hemisphere ziphiid species, Ramari's beaked whale, Mesoplodon eueu , whose name is linked to the Indigenous peoples of the lands from which the species holotype and paratypes were recovered. Mitogenome and ddRAD-derived phylogenies demonstrate reciprocally monophyletic divergence between M. eueu and True's beaked whale ( M. mirus ) from the North Atlantic, with which it was previously subsumed. Morphometric analyses of skulls also distinguish the two species. A time-calibrated mitogenome phylogeny and analysis of two nuclear genomes indicate divergence began circa 2 million years ago (Ma), with geneflow ceasing 0.35–0.55 Ma. This is an example of how deep sea biodiversity can be unravelled through increasing international collaboration and genome sequencing of archival specimens. Our consultation and involvement with Indigenous peoples offers a model for broadening the cultural scope of the scientific naming process.

Middle Ordovician Drepanoistodus (Vertebrata, Conodonta) from Baltica, with description of three new species

Drepanoistodus basiovalis (Sergeeva, 1963) is a common conodont species in Middle Ordovician strata of Baltica. For many years it has been widely accepted that the species encompasses a wide range of morphological plasticity. Hence, several different morphotypes that significantly deviate from the holotype have nonetheless been included in the broad species concept. In this study, we performed a detailed taxonomical study on 112 predominantly well-preserved specimens (geniculate elements) from the St. Petersburg region of Russia; 37 of these were selected for morphometric analyses together with 21 well-illustrated specimens from the published literature. The results demonstrate that, among the morphotypes that share some characteristics with D. basiovalis sensu lato, at least five species can be readily distinguished. Hence, three new species – Drepanoistodus iommii sp. nov., D. svendi sp. nov. and D. viirae sp. nov. – are here added to the previously known D. basiovalis and D. contractus (Lindström, 1955). In addition, some specimens were left under open nomenclature and assigned to Drepanoistodus aff. basiovalis and D. cf. suberectus (Branson &#38; Mehl, 1933). In order to objectively compare the Drepanoistodus taxa and test the validity of the new species, we performed a Principal Component Analysis combined with non-parametric (PERMANOVA) tests based on 21 morphological characters.